One type of earplug includes a soft foam body that is to be inserted into a person's ear canal to block noise. To help push the soft foam body into the ear canal, a stiffener of material stiffer than that of the foam body, is placed in the body. One way to place the stiffener in the body is to mold the body around the stiffener. U.S. Pat. No. 5,573,015 by Williams forms a long rod of stiffener material and passes it though an extrusion head while foam material is extruded around the rod and the resulting extrusion is cut into earplugs. This has the disadvantage that the rod front end lies at the front end of the earplug, resulting in a concern of people that the rod will scrape against the ear canal during insertion therein. Also, the stiffener rod is of uniform diameter and cannot produce the desired stiffness during insertion combined with flexibility to bend.
One type of earplug with stiffener, shown in U.S. Pat. Nos. 5,188,123 and 4,774,938, includes a largely hemispherical earplug body and a thin rod with a front end embedded deeply in the body. All of the hemispherical body is inserted into the ear canal, and it requires little foam material. The rod front end forms a stiffener, and the rod rear end forms a handle that can be grasped to push in and pull out the body from the ear canal. There is a possibility that the rod will separate from the body and leave the body in the ear canal. It would be desirable if the exposed rod rear end were molded for attractive shape, and the rod front end were molded intimately into the body to assure very good bonding of the rod to the body.